Process for treating fatty oils



Patented Jan. 11, 1949 2,458,554 raocnss FOR TREATING FATTY oms Don Sheldon Bolley, Brooklyn, and Edwin Charles Gallagher, Freeport, N. Y., assignors to National Lead Company, New York, N. Y., a corporation of New Jersey No Drawing. Application October 18, 1945, Serial No. 623,166

3 Claims. (Cl. 260-424) This invention relates to improvements in methods of purifying and bleaching fatty oils.

Fatty oils are often treated prior to use with bleaching agents to remove, coloring matter and certain other impurities. The bleaching earths employed for this purpose include adsorbent clay, bleaching clay, fullers earth, and the like and in the bleaching treatment, these are mixed with the oil and allowed to remain in contact with the 01] sometimes at an elevated temperature for varying periods of time, They are subsequently removed from the oil, for instance, by filtration or centrifuging, or in any other convenient manner. The coloring matter and other ir purities are removed by direct adsorption on the clay.

Some fatty oils, particularly the drying oils used in the varnish industry, contain certain impurities such as phosphatides, which leave a residual ash when the oil is burned. These ashforming substances, when present in an oil which is to be heat bodied, often cause either a precipitation during heating called break, or excessive frothing. Hence it is desired to re.- move these ash-forming substances before the oil is heat bodied, and it has been found that they are adsorbed and removed by certain bleaching earths. The present invention constitutes a simple and effective means for removing the ashforming material, coloring matter, and like impurities from fatty oils.

It is an object of the present invention to provide a method for producing fatty oils having a light color. Another object of the invention is to provide a method for producing fatty oils having a reduced ash content. A third object of the invention is to provide a method for producing fatty oils having a light color and. a reduced ash content. These and other objects of the invention will become apparent from this description.

The present invention in its broadest aspect comprises first admixing asmall amount of a strong mineral acid with a fatty oil and adding thereto a bleaching earth and after the bleaching earth has remained in contact with the oil for a desired period of time, removing the earth from the so treated oil.

, By the term strong mineral acid as used herein is meant an inorganic acid which is practically completely ionized with respect to the first hydrogen. The preferred acid to use in the practice of the invention, from the point of view of freedom from reactivity'with the oil, is sulfuric oil. Nitric acid is not recommended because at practically all concentrations it reacts with the oil.

The invention may be employed for the treatment of fatty oils generally for the bleaching thereof and removal of ash-forming impurities, for example, fatty oils such as linseed, soybean, cottonseed, peanut, corn, olive, palm, perilla, castor and sardine oils. The bleaching earths useful in the practice of the invention are those commonly employed for bleaching fatty oils, e. g. the so-caliecl adsorbent or bleaching clays, fullers earths, and the like.

The improved results of the present invention are obtained within a wide range of acid concentration, The concentration should be selected to yield the optimum results without adverse effect, for instance, charring of the oil. Thus the concentration, especially for sulfuric acid, may vary between about 10% and about 75%, preferably between about 40% and 60%, say about 50%. The amount of acid to be employed may vary from 0.045% to about 5.0%, preferably between about 0.1% to about 2.0%, based on the weight of the oil treated. inasmuch as the bleaching earth isv removed from the oil the amount employed is of no particular consequence. Good results are obtained using as little as about 2.0% up to about 10%. In commercial operations about 2.5% is satisfactory; on a smaller scale about 5.0% may be used. 7

In practicing the invention the acid is added to the fatty oil and the mixture agitated for sufficient time to disperse thoroughly the acid in the oil, which generally takes from about two to about ten minutes, or longer if desired. Then the bleaching earthis added and the agitation is continued for a time, sufficient to reduce the ash content to a desired low limit, for instance from about ten minutes to'about two hours, or even longer, if necessary. Elevating the temperature during the bleaching earth treatment tends to shorten the requisite time of treatment and enhance the improved results. Thus, it is desirable after adding the bleaching earth to raise the temperature of the batch to between about C. and C.

The following examples illustrate the invention without limitation,

EXAMPLE I Procedure.-To 500 grams of raw linseed oil which the acid was thoroughly dispersed in the RESULTS oil. Five per cent of a grade No. 1 bleaching earth (bleaching earths are graded according to their lfovibond Wesson color bleaching efficiency: grade No. 1=good; grade No. 2=medium; grade No. 3:poor) was added to the 5 Red y n agg acid-oil mixture and while a itating, the ternperature was raised to about 100 C. and held at Oil before treatment 1.8 20 (5V inch column) 0.000 that point for about ten minll-les- The on was OiI aiter treatment oiEx. 1.1 12 (5V: inch column).. 0.000 then filtered to remove the bleaching earth. For

. Oil idt t t i- 1.5 155 1111 0.000 purposes of comparison, the exper1ment.was re- .3? Tea men mm (A no mum) peated omitting the acid treatment.

RESULTS EXAMPLE VI Lfl m d Wesson C0101 Procedure-Same as for Example I, but substituting a refined cottonseed oil and using a RM W10. Pefglclnt grade No. 3 bleaching earth.

RESULTS Oil heforelruetnlcut as no (1 inch column). 0.112 Lovibond Wesson color Oil after treatment of Rx. 5.0 25 (5% inch column). 0.005

1. OitlUlLoid treatment. oluit- 5.5 30 (5% inch column) 0.05 29 Red Yel o aga l Tim Lovllmnri Wesson color detemltnrltion.The metho r mmmem 1 8 1 inch column) 0 000 ml and apparatus was adopted by the American Oil Chemr 1 f isgign' (m May 1 034 l d g tf fi gh (A Ollflll'tcr treatment of? 1. 1.4 1.16 inch column) 0.000 veer p on appears in tle leia an en a ve e 0 s 1 of flu; lm g'imu Oil Chemists Society" revised to Jan- "fitment 14 2064mm column)" llill EXAMPLE II WXAMP Procedure-Same is for Example I, but sub- LE VII stituting a grade No. 2 bleaching earth 3o Procedure.Same as for Example I, but sub- RESULTS stituting raw soybean oil and using a grade No. 1 bleaching earth. novibond Wesson color RESULTS Lovibond Wesson. color Red Yellow 342 85 R d Y 1] w Perm Oil before treatment .1 3.3 30 (1 inch column) 0.112 e e 0 Ash OlIlIafter treatment of Ex. 8.5 55 (5% inch column)... 0.018

- Oil before treatment 6.0 (1 inch column) 0. 203 gf treatment omit 55 (5% inch column) 061 40 oillafiter treatment of Ex. 10.6 40 (5% inch column). 0.065 Oil acid treatment 14.8 55 (5% inch column) 0.082 EXAMPLE m Procedure.--Same as for Example I, but substituting a grade No. 3 bleaching earth. EXAMPLE VIII RESULTS Procedure-Same as for Example I, but substitu in re. so bean oil an usin a rade No. 2 Lombond Wesson color bleactmgg z d g g P RESULTS Red Yellow x32 Lovibond Wesson color Oil before treatment 3.3 30 (1 inch column). 0.112 oillliiitcr treatment of Ex. 12.6 60 (54 inch column) 0.018 Red Yellow Pei-cant S Oil acid treatment omit- 70 (5 inch column) 0.090

e I 55 Oil before treatment 6.0 36 (Lincb column).... 0. an 0i l lgtler treatment of Ex. 15.0 55 (5% inch column) 0.093 EXAM} LE IV Oil .a'tld treatment 15.2 55(6Minch column)-- 0.125 Procedure.Same as for Example I, but submutedstituting a refined cottonseed oil and using a. grade No. 1 bleaching earth. EXAMPLE Ix Rnsum's L d W l Procedura same as for Example I, but subom 6330" CO stituting raw soybean oil and using a grade N0. 3

bleaching earth. Percent Red Yellow Ash 5 RESULTS 011 before treatment 1.8 20 5% inch column) 0.000 Lombond Wesson color oilleitertreatment of Ex. 0.9 10 (5%incb column). 0.000 Oil acid treatment omit- -1. 1 10 (5% inch column) 0.000 Red Yellow Per scfint ted. I '70 011 before treatment 6.0 35 (1 inch column) 0.203 EXAMPLE v Oil1iter treatment of Ex. 19. 4 (5% inch column). 0. 082 as Example! but on acid treatment 28.0 10 514mm column)... 0.12s stituting a refined cottonseed oiland using a om grade No. 2 bleaching earth. 745.

The foregoing examples all clearly show the improved results of the present invention resulting from the conjoint action of a small amount of a strong mineral acid and a bleaching earth on various fatty oils. The following example demonstates the superiority of the present invention over a procedure wherein the bleaching earth is heated with the acid.

EXAMPLE x Procedure.-Same as for Example I, using raw linseed oil and a grade No. 1 bleaching earth. In the comparative treatment the acid was mixed with the bleaching earth and this mixture added to the oil. In other respects, the procedure, 1. e. weights, time and temperatures were the same.

Rnsum's 'Lovibond Wesson color Red Yellow Per Oil before treatment 3.4 30 (1 inch column).. 0.121 DialI after treatment of Ex. 5. 6 (5% inch column)... I 0.005 Oil acid added to earth 6. 6 35 (5% inch column) 0. 039 oilattti 31 treatment 6.6 35 (5%incl1column)... 0.036

om: e

The improved results of the present invention apply also to refined oils,-such as acid refined linseed oil, as shown by the following example.

EXANIPIE XI Procedure-Same as for Example I, using an acid refined linseed oil.

Rssunrs Lom'bond Wesson color Red Yellow ig Oil before treatment- 3. 2 30 g! inch column) 0.000 olilaiter treatment of Ex. 4. 5 30 5% inch eolumn) 0. 000 on acidtreatmentomitted. 5. 3 so 5% inch column); 0.000

The use of hydrochloric acid in the practice of the present invention is illustrated by the following example which shows particularly the lowering of ash content.

EXAMPLE XII Procedure-Same as for Example I, but. sub- RESULTS Lovibond Wesson color Red Yellow ag Oil before treatment 3.0 25 (1 inch column) 0.153 Oil alter treatment of Ex. 5. 6 30 (5% inch column) 0.082 011 aeidtreatmcntomitted. 4. 4 a0 5% inch eolumn) 0.099

From the foregoing description of the present invention, it will be obvious to those skilled in this art that the present invention is capable of considerable modification with respect to the variety of fatty oils to which it is applicable; with respect.

to bleaching earths and acid employed, and the like, all within the scope of the appended claims.

We claim: 1. A method for refining fatty oils which comprises admixing between about 0.045% and 5.0%

by weight of sulfuric acid having a concentration 7 tration between about 40% and 60% to an impure stituting 0.25 per cent, by weight of 18 per cent hydrochloric acid.

fatty oil, agitating the mixture to disperse the acid in the oil, incorporating bleaching earth in the oil-acid mixture and, while agitating the mixture, heating it to a temperature between about C. and about C., and maintaining the mixture at that temperature for a suflicient length of time to efiect a reflnement of the oil, and separating the so-treated oil from the bleaching earth.

3. Method according to claim '2 wherein the fatty oilis raw linseed oil.

DON SHELDON BOLLEY.

EDWIN CHARLES GALLAGHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 1,808,755 Baylis June 9, 1931 2,296,850 Harrison Sept. 29, 1942 2,410,926 Bush et al Nov. 12, 1946 FOREIGN PA'I'ENTS Number Country Date 377,336 Great Britain July 28, 1932 

